Nadiya Savchenko was sentenced to 22 years in prison over fatal shelling of two Russian reporters in east Ukraine.
Photograph: Anadolu Agency/Getty Images

Ukrainian military pilot Nadiya Savchenko, convicted over the killing of two Russian journalists, has begun another hunger strike to demand her return to Ukraine, her lawyer said.

Lawyer Mark Feigin wrote on Twitter that Savchenko had started a “dry” hunger strike – refusing both food and water – on Wednesday morning, after posting a letter from her demanding her “immediate return” to her homeland.

“She is not drinking,” Feigin confirmed to AFP on Wednesday.

A Russian court last month found the 34-year-old pilot guilty of involvement in the fatal shelling of two Russian state television reporters in east Ukraine and sentenced her to 22 years in prison.

Savchenko has maintained her innocence but refused to appeal against the verdict, saying she did not recognise the authority of the Russian legal system. She has gone on several hunger strikes throughout her detention and high-profile trial.

Her case has prompted condemnation from the European Union and Washington, which have called for her release.

Savchenko – who has become a national hero in Ukraine and has been elected to parliament in absentia – is incarcerated in a detention centre in southern Russia. Her sentence formally entered into force on Tuesday and Russian law requires she leave for a prison camp within 10 days unless she is swapped or extradited to Ukraine.

Ukraine’s pro-western president, Petro Poroshenko, spoke to Savchenko by telephone on Tuesday and informed her about “the latest steps taken for her release”, a statement on his website said.